Power lift



Jan. 16, 1951 BROWN 2,538,143

POWER LIFT 2 Sheets-Sheet 1 Original Filed Feb. 1, 1943 V INVENTOR. I50 THEOPHILUS BROWN Jan. 16, 1951 T. BROWN POWER LIFT Original Filed Feb. 1, 1943 2 Sheets-Sheet 2 Ea/fiN /fi\F INVENTOR. T HEOPH l LU S BROWN if A A Patented Jan. 16, 1951 POWER LIFT Theophilus Brown, Moline, Ill.', assignor to Deere & Company, Moline, Ill., a corporation of Illinois Original application February 1, 1943, Serial No.

474,404, now Patent No. 2,416,373, dated February 25, 1947.

Divided and this application November 30, 1945, Serial No. 632,076

18 Claims. 1 This application is a division of my-copendin application, Serial No. 474,404, filed February ,1, 1943, now U. S. Patent 2,416,373, issued February 25, 1947. V

" The present invention relates generally to power lift mechanism for agricultural tractors and the like, and more particularly to hydraulic mechanism including two separately operable ram units. 'The object and general nature of the present invention is the provision of hydraulic mechanism including a pair of ram units with control means therefor-so constructed and arranged that the ram units may be simultaneously operated and controlled or operated and controlled separately or individually. A further feature of this invention is the provision of a pair of ram units each having means for returning the controlling valve to a neutral position after a given amount of extension of the ram unit.

A further feature of this invention is the provision of hydraulic mechanism including a pair of ram units, each having its own individual control; with means shiftable from one position, in

which both controls are operated together, into another position in which the controls may be operated individually. More specifically, it is a feature of this invention to provide a hydraulic arrangement of this kind in connection with a single source of power, such as a positive displacement pump, with a bleeder valve arranged in the system for diverting a quantity of fluid when only one ram unit isextended, the bleeder valve being adapted to-be automatically closed when both ram units are operated together, whereby the time of operation, whether both units together, or only one, is the same in both cases or substantially so.

These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which:

Figure 1 is a perspective view of the rear portion of an agricultural tractor equippedwith hydraulic apparatus of the present invention in which two ram units are associated with a single. source of fluid pressure such as a pump, with optionally controlled means for operating the two ram units either separately or simultaneously;

Figure 2 is a fragmentary top view of the shiftable valve control handle; and

Figure 3 is a diagrammatic view of the valve mechanism.

Referring now to the drawings; particularly Figure '1, the structure chosen to illustrate. the

principles of the present invention includes a main hydraulic power lift unit I50 adapted to operate a pair of implement controlling members I suitably connected with a tool or tools, such as cultivators or the like, whereby the tool or tools may be raised or lowered simultaneously or inde+ pendently. This mechanism is similar to the mechanism shown in my United States Patent No'. 2,337,638, issued December 28, 1943, to which reference may be made if necessary. In the present form of the invention the hydraulic unit I50 is substantially identical with the hydraulic unit disclosed and claimed in the co-pending application filed August 6, 1942, by Wayne-H. Worthington, Serial No. 453,907, new U. S. Patent 2,403,422, 'It will therefore be unnecessary to completely describe the unit I50 except to say that a g ear'pump I5I serves as a source of fluid under pressure for'delivering oil under control-of suitable valve mechanism to a cylinder and piston orram unit arranged similar to the power lift mechanism shown in the prior United States patent-to E. McCormick et al., No. 2,107,760, dated Feb'ruary8, 1938, to which reference may be made if necessary.- The piston of such a unit is connected through an arm to a transverse rockshaft I that is mounted for-rocking movement in a housing I55 having lateral extensions I5'I, 'there being only a single rockshaft'in this form of the invention, Preferably, the rocksha'ft I55 is square in cross section but it may be formed otherwise,

if desired. At-the left side of the tractor, indicatedby the reference numeral Ia, an arm I59 is fixed by any suitable means to the left end'of the rockshaft I55, and at the other end of the latter,- a bell crank I6I is mounted for rocking movement, preferably on a journal or bushing I62 which provides for movement of the bell crank I6'I relative toithe rockshaft I55. The bell crank Iiil is held inpositionbetween the outer end of the right lateral extension I51 and a collar I53 fixed to the rockshaft I55. Connected to'the left arm .159 is'a cultivator lift pipe I65;and.the

arm I59 mayhavea rearward extension I66 to l which reanrigs may be connected. The bell crank I6I at the other side ,of' the tractor is alsolcon nected toga'cultivator push .pipe I61, and likewise the ,bell, crank I5,I- is provided with a rearward extension-II,I, to which other rear rigsmay-be connected if desired, the extension I'II forming a part of the rearwardly extending arm .I'ILthat includes a bifurcated portion I13 which is aperturedito receive a pivot pin I14. An auxiliary ram unitjlfi is anchored atits, lower end to a bracket connectedtopr carried by the tractor .la; and the movable piston unit I11 of the ram unit I16, is connected by a link or strut I18 to the pivot I14. Fluid flows to the ram unit I16 through a flexible hose connection I8 I, connected into the valve box I82 that forms a part .of the hydraulic unit I50.

The valve mechanism enclosed in the casing I82 and the operating and controlling means therefor is, in thi form of the invention, quite similar to the valve means shown in my parent application, identified above, and the valve mechanism shown in the above-mentioned Worthington co-pending application. It is therefore sufiicient to note that, in this form of the invention, the hydraulic unit I58 incorporates means that causes fluid to be directed under pressure into the cylinder in which the piston controlling the rockshaft I55 is movable, such valve mechanism also incorporating :similar means controlling the flow of fluid to and from the auxiliary ram unit I16. As best shown in Figure l, the first mentioned controlmeans includes a hand lever I85 having its lower section in screw-threaded engagement with the .upper end of an arm I86 that is connected directly to and forms a part of the valve mechanism controlling the ram unit that rocks the rockshaft 155. .A return cam I81 is fixed to a shaft carried by the casing I82 and is operatively connected with the piston associated with the rockshaft I55 so as to be moved in a forward direction so as to engage a flange I89 formed on the hand lever I85 and return the latter to .a neutral position when the piston reaches a given point in its forward movement, depending upon the adjustment of the member I85 on the member I86. The hand-lever for controlling the auxiliary ram unit I16 is indicated in Figure 1 by the reference numeral I95 and includes a lower section that is threaded onto an .arm I96 that is connected directly with the valve mechanism controlling the flow of fluid to and from-the ram 116. A return cam I98 is formed on a rock- ,able member I99 that is connectedby a link 20I .with the piston section I,18 of the ram I16, whereby when the valve is in a positionpermit- .ting fluid to flow from the .ram back to the sump, the resulting movement .of the piston section causes the member I99 to rock in a direction to carry the cam I98 into engagement with the lower end of the handilever I95 and to return the latter to. a neutral position at a point in the cycle of operation which depends upon the position of adjustment of the member I95 'on the threaded arm I96. The particular .valve :mechanism incorporated in the hydraulic .unit I58 is shown diagrammatically in Figure 3 and .will be referred .to in detail below. It will be .understood that the particular details of the valve mechanism do not .perse form apart of the pres- ;ent invention except in combination with other novel features.

Thevalve operating handle :I85 and the member I86 .on which it is mounted are disposed for lateral movement toward and away from the casin I 82 while maintaining operative connection .with the valve mechanism in the casing I82, and the flange I 89 is of sufiicient radial extent so :that in any position of the member I85, I86 the cam I81 is adapted :to engage the flange I89'and restore the valve handle I85 to its neutral position, as described above. Aconnecting member, indicated in its entirety by the reference numeral 2I8, is mounted for sliding and "rocking movement on the casing I82, the latter :hav-

ing one or more apertured lugs in which the central part of the member 2I8 is preferably disposed. The left end of the member 2I0 has a grooved section 2I2 which meshes with a pinion 2i 3 disposed *on the upper end-:ofa bleeder valve shaft 2 I4, there preferably being a splined or similar connection between the pinion 2I3 and the valve stem 2I4 for a reason which will appear below. At the left of the grooved section 2I2 the member 2I8 carries an arched portion 2I6 which terminates in a loop 2I1 disposed about the lower portion of the valve handle I in a fairly snug fitting relation but with sufficient looseness that the rocking movement of the valve handle I85 in a fore and aft direction causes the member 2I8 to rock about its axis of support in the lug 2| I. At the other end of the member 2I8 a forked section 2I9 is disposed and has arms 22I adapted to embrace the other valve operating handle I95. The member 2I0 is mounted for slidin movement in a lateral direction from a position in which the arms 22I clear the valve handle I into a position in which the latter valve is operated whenever the member 2I0 is rocked about its axis of support on the casing I82. The member 2I8 is shifted laterally by the lateral shifting movement of the valve operating member I85, I 86, and whenever the member 2I8 is shifted the pinion 2I3 and the valve stem 2I4 is rotated, and this action is utilized according to the present invention to secure a readjustment of the hydraulic system to provide for operating the two ram units over their full stroke in substantially the same time that either may be operatedsingly.

'The valve mechanism incorporated in the unit E58 is shown diagrammatically in Figure 3 and, as mentioned above, is of substantially the same construction as is shown and claimed in the Worthington co-pending application, identified above. Referring now to Figure 3, rocking the handle I85 in the direction indicated F in Figure 1 (forward), raises a valve 252 and closes off an idle passage 253 leading to a sump S and diverts oil under pressure through a passage 254 .past a check valve 258 and out into a passage 259 to the ram unit that rocks the rockshaft I55. Rocking the handle I85 in the other direction R '(rearwardly) causes the lower end of the valve 252 to open the check valve 258, permitting oil to flow out of the ram unit associated with the rockshaft through passages 259 and 25 3 back .to the sump S.

When the valve lever I85 is swung in direction R to lower the valve.252 and fluid flows .from the ram unit through passages 258 and .253 to the sump S, the resulting movement of the piston of the ram unit permits the rockshaft 55 to rock in a direction to swing the arm I59 rear- ,wardly, thus lowering the tools associated therewith Ajlink 260 is connected to be shifted whenever the rockshaftl55 rocks in a rearward direction and this, in turn, rocks the return cam member E81 (Figures land 3) which, as described above, engages the flange I89 and returns the valve handle I-85, and the associated valve mechanism, to .a neutral or intermediate position. The parts are so arranged that when the rockshaft I55 reaches a given point in the lowering direction, depending on the adjustment of .the handle I85 on the arm I86, the cam member I81 acts against the flange I89 and the arm I86 and raises the valve 252 to its neutral position, thus automatically terminating the lowhandle I95 and the associated arm I96 and, in. general, operates in the same way as described above in connection with the valve 252, namely,

either to direct fluid under pressure through pas'- sages 254a and 212 to the flexible hose I8I lead-.

ingto the auxiliary ram unit I16, or to permit fluid to flow from the latter unit back to the. sump S. Acting through the link 2M, when thevalve 252a is lowered to permit fluid to flow from the ram unit I16, the resulting movement of the piston element I18 and the link 20I causes the cam I98 to approach the lower end of the valve handle I95, thus serving to automatically return the valve 252a to a neutral position whenever the piston of the ram unit I16 moves to a pre determined position, depending upon the adjust ment of the member I95 on the member I95- "'It was described-above how the left valve operating handle I85 may be shifted laterally into aflposition to disengage the section 2I9 of the laterally shiftable member 2") from the valve operating handle I95. In this position of the partsyeither of the valves 252 and 252a may be operated separately, as may be' desired; E101 example, where right and left hand cultivator rigs are connected with the arms I59 and IBI, the outfit may be employed for cultivating point rows, one'valve operating handle being used to raise the tools at one side while permitting the outfit to travel a further distance before operating the other valve handle to raise the tools at the other side.

It may also be desirable to raise and lower'th tools at the same time, and according to the present invention this may be done easily and conveniently merely by shifting the valve handle I85 to the right, which acts through theshiftable member 2H! to move the section 2 I 9 into engagement with the other valve handle I95. Then by rocking either valve handle I85 or I95 forwardly, both valves 252 and 252a will be placed in a position to raise the tools at both sides of the tractor at the same time, and swinging either valve handle I85 or I95 rearwardly will therefore actuate both valves to lower both sets of tools. Where the tractor is equipped with hydraulic power lift mechanism of the type described above, namely, one or more ram units with 'a pump of the positive displacement type driven at more or less a constant speed, the simul-' taneous connection of both ram units to the single source of power would result in operation at approximately twice the time that would becurr when either of the ram unitsis operated independently, for the reason that the simultaneous operationof both units requires twice as much oil as the separate operation of one unit. According to the present invention, I provide means whereby the length of time required to operate either ram unit is substantially the same as the length of time required to operate both together, Briefly, the present invention con-, templates installing a bleeder valve in the high pressure line and to control the open and closed position of the bleeder valve by the shifting movement of the member 210 so that an amount of oil is diverted from the system when only one ram unit is operated, but when both ram units are operated simultaneously the bleeder valve closed so as'to utilize the full capacity of the pump to raise both l I 6, As best shown in Figure l, the upper end of the bleeder valve stem 2 I4 is threaded, the threads being fairly coarse and the corresponding portion of the casing receiving the valve stem 2M being correspondingly threaded. The lower end of the stem 2M is formed as a needle valve, as indicated at 230 and cooperates with a bleeder opening 231 formed in the passage 232 leading from the pump to the high pressure passage 253. Thus, whenever the member 2H] is shifted in one direction or the other, the valve stem2I4 is raised or \lowered, opening or closing the bleed passage 23k The capacity of the bleed is such that when the valve is open, suflicient oil is di-.

verted so that one ram unit may be operated through its full strokein approximately the same time that both ram units are operated when the valve is closed. To adjust the bleeder valve, the pinion 2 I3 may be raised on the splined upper end of the stem 2 I4 and out of mesh with the grooved section 2I2 to permit turning the pinion .to a new position of adjustment before remounting it on the upper end of the stem 2 I4.

While I have shown and described above the preferred structure in which the principles of the present invention have been incorporated, it is to be understood that my invention is not to be limited to the particular details shown and described above, but that, in fact, widely different means may be employed in the practice of the broader aspects of my invention.

What I claim, therefore, and desire to secure by Letters Patent is:

l. A power lift device for agricultural tractors and the like, comprising a pair of ram units normally separately operable, each having controlling valve means therefor and a part for operating the valve means, a separate hand lever for operating each valve part, one of said hand levers being movable in one plane into either of two positions and also movable in either position in another plane generally transversely relative to said one plane in a direction to operate the associated valve part, and means movable with said hand lever when the latter is moved in said one plane into engagement with the other hand lever, said means being then movable with said one hand lever when the latter is moved in said other plane, whereby both of said hand levers may be operated together.

'2. A power lift device for agricultural tractors and the like, comprising a pair of ram units normally separately operable, each having controlling valve means therefor, optionally operable means adapted to actuate said valve means simultaneously or separately, and means controlled by said optionally operable means for maintaining substantially constant the application of power deliverable to each of said ram units, according to whether they are actuated only one at a time or simultaneously actuated.

:5. A power lift device for agricultural tractors and the like, comprising a single source of fluid pressure, a pair of rain units normally separately operable, each including controlling valve means therefor, optionally operable means adapted to actuate said valve means either simultaneously or separately, a bleeder valve movable from open to closed position and adaptedwhen open to divert a quantity of fluid when said ram units are operated separately, and means actuated by said optionally operable means for closing said bleeder valve when both of said ram units are operated simultaneously.

7 4. A power lift device for agriculturaltractors 7. and the like :having a source ;of fluid zpressure, comprising apair of ram units normally separately operable, each having controlling valve meanstherefor anda part for operating the valve means, a fluidconnection between said source and said valvermeans, a separate member for operatlng each valve .part, one of said members being movable in two planes, means operatively connected with said one member and shiftable into a position engageable with the other member wherebymovement of said one member serves to operate .cboth members, and fluid flow modifying means actuated by movement of said shiftable means out'ofsaid position for diverting a portion of the fiuid flow from said source when said valve parts: are operated separately.

;5. :In a valve :mechanism including two valve units, each having a separate movable valve controlling member and one of said members being movable into either of two positions and also movable in either position in a direction to operate ;the associated valve part, means movable with said one member into engagement with the other member so as to provide for operating both of said members by moving either of them, a source of fluid under pressure, connections between .said source and said valve units whereby fluid flow from said source .is controlled, and means actuated by said movable means for diverting a portion of said flow when only one of said valve units is .operated.

6..In an agricultural machine or the like, a pair of normally separately operable .control members movable normally in parallel spaced apart planes, and one of said members being movable in a transverse direction into either of two positions, a part having one end interconnected with said one member and movable with said one member from one of said transverse positions tothe other, the other end of said part having means engageable with the other control member in one position of said one control member whereby both of said members will be operated when said one member is operated, and a thirdmember interconnected with said part and shiftable from one position to :another when said part is moved.

*7. :In .an agricultural machine or the like, a pair of normally separately operable control levers movable normally in parallel spaced apart planes,.and one of said levers being movable in a'transverse direction into either of two positions, a part having one end interconnected with said one lever and movable with said one lever from oneofsaid transverse positions to theother, the other end of said part having means engageable with the other control lever in one position of said one control lever whereby both of said levers will be operated when said one lever is operated, and asupport upon which said levers are mounted for movement about a common axis and said part interconnecting said levers being mounted for movement about an axis adjacent said first axis.

8.The invention set forth in claim 7, further characterized by a hydraulic bleed valve unit operatively connected with said part and opened and closed by movement of the latter correspondingtolniovement of said one member between said transverse positions.

9. A power lift device for agricultural tractors and the like, comprising a pair of ram units normally separately operable, each having controlling valve means therefor, means for operating both of :said valve means simultaneously so as to and the like, comprising a pair of ram units normally separately operable, each having controlling valve means therefor, mechanism for operating said valve means including a part shiftable from one position, in which either of said valve means may be operated separately, into another position in which said two. valve means are operated simultaneously, and means controlled by movement of said part for maintaining substan-v tially constant the rate at which fluid is supplied to each ofsaid ram units.

11. In an agricultural implement, a support, a pair of levers mounted thereon in spaced apart relation for optionally independent rocking movement about a common axis, a connecting part extending between said levers and mounted on said support for both transverse sliding movement and rocking movement about an axis disposed co-directionally with respect to said first axis, one of said levers also being mounted on said support for lateral shifting movement toward and away from the other lever, means on the end of said part connected with said one lever to cause said part to be both rocked and shifted laterally with said one part, and means on the other end of said part to embracingly connect the latter with said other ,lever when said one lever and said part are shifted toward said other lever, whereby when the two levers are so connected rocking of said one lever acts through said connecting part to rock the other'lever.

'12. In an agricultural implement, a support, a pair of levers mounted thereon in spaced apart relation for optionall independent rocking movement about a common axis, a connecting part extending between said levers and mounted on said support for both transverse sliding movement and rocking movement about an axis disposed codirectionally with respect to said first axis, one of said levers'also-being mounted on said support for lateral shifting movement toward and away from the other lever, an arm portion on one end of said part embracing said one lever so as to cause said part to be both rocked and shifted laterally with said one part, and a forkportion on the other end of'said part to embracingly connect the latter with said other lever when said one lever and said part are shifted toward said other lever, whereby when the two levers are so connected rocking of said one lever acts through said connecting partto rock the other lever.

13. A power lift device for agricultural tractors and the like, comprising a support, a single source of fluid pressure, a pair of ram units normally separately operable, each including controlling valve means therefor, means for operating said controlling valve means including a pair of levers mounted on said support in spaced apart relation for optionally independent rocking movement about a'common axis, a connecting-part extending between said levers and mounted on said support for both transverse sliding movement and rocking movement about an axis disposed co-directionally with'respect to said first axis, one

of said levers also being mounted on said sup-' port for lateral shifting movement toward and away from the other lever, a bleeder valve movable from open to closed position and adapted when open to divert a quantity of 'fluid when said ram units are operated-separately, means-on the end of said part connected with said one lever to cause said part to be both rocked and shifted laterally with said one part, means on the other end of said part to embracingly connect the latter with said other lever when said one lever and said part are shifted toward said other lever, whereby when the two levers are so connected rocking of said one lever acts through said connecting part to rock the other lever, and means on said part for closing said bleeder valve when both of said ram units are operated simultaneously.

14. For use with a power lift device which includes a fluid pump, a ram unit, and control means including a valve controlling part, the improvement which comprises a second ram unit adapted to be connected to receive fluid under pressure from said pump, control means for said second ram unit including a valve controlling part, means for operating both of said valve controlling parts simultaneously so as to operate both of said ram units, simultaneously, and means controlled by said operating means for retarding the operation of either of said ram units when one is operated without the other.

15. For use with a power lift device which includes a fluid pump, a ram unit, and control means including valve means, the improvement which comprises a second ram unit adapted to be connected to receive fluid under pressure from said pump, control means for said second ram unit including valve means, mechanism for operating said two valve means including a part shiftable from one position, in which said two valve means may be operated separately, into another position in which said two valve means are operated simultaneously, and means controlled by movement of said part from said other position to said one position for diverting from said ram units a portion of the power that is normally deliverable to said units when they are operated simultaneously.

16. For use with an agricultural tractor which includes a single source of fluid pressure, a ram unit, and valve means controlling the flow of fluid to said ram unit, the improvement which comprises a second ram unit adapted to receive fluid from said source, valve means for controlling the flow of fluid to said second ram unit,

means for operating said controlling valve means 1,

including a pair of levers adapted to be mounted on the tractor in spaced apart relation for optionally independent rocking movement about a common axis, a connecting part extending between said levers and adapted to be mounted on the tractor for both transverse sliding movement and rocking movement about an axis disposed codirectionally with respect to said first axis, one of said levers also being adapted to be mounted on the tractor for lateral shifting movement toward and away from the other lever, a bleeder valve movable from open to closed position and adapted when open to divert a quantity of fluid when said ram units are operated separately,

means on the end of said part connected with said one lever to cause said part to be both rocked and shifted laterally with said one part, means on the other end of said part to embracingly connect the latter with said other lever when said one lever and said part are shifted toward said other lever, whereby when the two levers are so connected rocking of said one lever acts through said connecting part to rock the other lever, and means on said part for closing said bleeder valve when both of said ram units are operated simultaneously.

17. A power lift device for agricultural tractors and the like having a fluid pump, an inlet and an outlet for said pump, and a reservoir with which said inlet is in communication, said device comprising a pair of ram units connected with said pump outlet and normally separately operable, each having controlling valve means therefor, optionally operable means adapted to actuate said valve means simultaneously or separately, and means controlled by said optionally operable means for diverting some of the fluid from the pump outlet to said reservoir when actuating said valve means separately.

18. A power lift device for agricultural tractors and the like having a fluid pump, an inlet and an outlet for said pump, and a reservoir with which said inlet is in communication, said device comprising a pair of ram units connected with said pump outlet and normally separately operable, each having controlling valve means therefor, mechanism for operating said valve means including a part shiftable from one position, in which said valve means may be operated separately, into another position in which said two valve means are operated simultaneously, controllable means for diverting a portion of the fluid from said pump outlet to said reservoir, and means controlled by movement of said part between said positions for actuating said controllable fluid-diverting means.

THE'OPHILUS BROWN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED, STATES PATENTS Mott Apr. 29, 1947 

